1. Field of the Invention
The present invention is directed to an interface system that interfaces opto-electronic devices and fibers, particularly using passively aligned optical elements and mechanical interface.
2. Description of Related Art
There are numerous ways to couple light to and from opto-electronic devices and fibers. One typical manner in which this is achieved is to butt couple the opto-electronic devices right up against the end faces of the fiber. Such butt-coupling requires active alignment to achieve desired levels of coupling efficiency. Further, butt-coupling does not allow the light beam to be modified. Finally, such butt-coupling typically requires close positioning of the opto-electronic devices in accordance with the spacing of the fibers, increasing crosstalk.
Another manner of achieving coupling between fibers and opto-electronic devices is to use short fibers, which in turn are coupled to the fibers. This allows surface emitting opto-electronic devices to be coupled with fibers, but still requires active alignment.
One passive alignment scheme proposed involves providing holes in all of the components to be aligned, e.g., a ferrule housing the fibers, a light coupling device including optics and a substrate including the opto-electronic devices. Pins are then inserted into the holes to realize alignment of all the elements. Such single shot alignment may not be accurate enough for all applications. Further, the materials that can be used for the light coupling device are limited when the holes need to be provided therein. Finally, such alignment requires that there be a linear relationship among all of the components.
The present invention is therefore directed to an interface that substantially overcomes one or more of the problems due to the limitations and disadvantages of the related art.
It is an object of the present invention to provide a easily manufacturable scheme for aligning optical elements between opto-electronic devices and fibers.
It is another object of the present invention to use an existing feature in the system as part of the alignment of the optical elements.
At least one of the above and other objects may be realized by providing an interface system between an opto-electronic device and a fiber in a housing, the interface system including an optics block having at least one optical element formed therein for coupling light between the fiber and the opto-electronic device, a mechanical interface which aligns and mates the housing, the mechanical interface including an aperture between the optics block and the housing, light being transmitted between the optics block and the fiber through the aperture and the optics block, and mechanical alignment features on the optics block, the mechanical alignment features protruding from the optics block, at least one mechanical alignment feature on the optics block abutting with at least one sidewall of the aperture. The mechanical interface is separate from the optics block and the housing. At least part of the mechanical interface is disposed between the optics block and the housing. The mechanical interface includes a first surface to be positioned adjacent to the housing and a second surface, opposite the first surface, to be positioned adjacent to the optics block.
The mechanical alignment features may be formed lithographically. The interface mechanical alignment features may be at least approximately 100 microns high. The mechanical alignment features nay be made of a photoresist, e.g., SU-8. The sidewalls of the aperture may be tapered. The mechanical alignment features may surround the optics on the optics block. The mechanical alignment features may completely surround the optics on the optics block. The mechanical alignment features may extend longitudinally along the optics block. The mechanical alignment features may be in corners of the optics block. The mechanical alignment features may be in a longitudinal center of the optics block. The mechanical interface may be opaque to light being coupled between the opto-electronic device and the fiber. The mechanical alignment features may be of a different material than the optics block. The mechanical interface may further include alignment features for aligning the mechanical interface with the housing. Each sidewall of the aperture may be abutted by a mechanical alignment feature, least two sidewalls of the aperture may be abutted by a mechanical alignment feature, or only three sidewalls of the aperture may be abutted. The mechanical alignment features on the optics block may allow translation of the optics block when in the aperture.
These and other objects of the present invention will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.